Kingdom.]

AND SURGICAL INSTRUMENTS.

461

North, North Central, and South Central Galleries.

^8 Edwards, John Baker, Liverpool —Producer andQ, , Manufacturer,

oth 6ries °I glass retorts, beakers, evaporating basins, andele 6r an( l porcelain vessels for chemical purposes,an f t i?' < i 0 PP ere ^' Vessels thus coated accelerate solutiondistillation, and require a minimum of beat to con-

duct these processes, while the copper conducting theheat equably over the surface of the glass, preserves itfrom fracture and unequal expansion, and at the sametime protects it from external casualties. The cut repre-sents several of these vessels.

cnmuii'.iiiURmmj*

Edwards’ Copper-covered Glass Apparatus.

^ t he covering of glass and porcelain vessels with copperfirst exhibited at the French Exposition in 1844.p e ® e vessels excited great curiosity, and occasioned much-pi P exing speculation as to the mode of their production,and coat ‘ n S °f metal was applied in so smooth, perfect,0 y uniform a manner, as to render it evident that nonein R 1 *- or ^ nar y methods of metallurgy had been adoptedheir manufacture. These vessels were coated by elec-ch . e P rocess > and similar apparatus is now made fore Rucal purposes in England. The surface of the glassjj Porcelain is first varnished, then brushed over with0 n ^-p°wder, in order to form a conducting surface onin tn t0 3 e P°sit the copper, and the vessel is then placedIn ^ ^ ecom position-cell, in connexion with a battery,hr' days the whole external surface is covered with& t metallic copper.—R. E.]

j -

A Rundell, W. W., Falmouth —Inventor andq , . Manufacturer.

borii- r j 0n ’. ze( l cast-iron magnet. The cast iron is car-a nd prussiate of potash and oil, and is hardened

snmii em Pered, by which the magnet is improved at a- 1 expense.

, Inn

c hinefy ess ' ons an< * s P ce 'imens of seals, executed by ma-

43 q „ -

oearder, J. N., 34 George Street , Plymouth —

, . Inventor and Manufacturer.

Pbcabl r ° n com P oun d horse-shoe permanent magnet, ap-appii ®.t° purposes requiring high magnetic power. Theof 24 i° n °f ca st iron is new. This magnet consiststli e f 0 P ates, 2 inches wide, •$. of an inch thick, cast inth 6 p 0 i riu a horse-shoe, which is lGf inches long froma Sl ,n ( , es 1 ° the outside of the bend; the poles are 1 J inches2q pj ' > au d the inside of the bend 3j inches wide. Thewith th 6 - S about 72lbs., and are fastened together

ca g( . • “ ree bolts and nuts. The poles are capped with6 Xtr ao °n’ w bich concentrates the magnetic power in anthe ^ r "inary manner. The construction is very simple:Saiiq rs are cast f rom No. 1 pig iron as hard as greenan make them, and they require no preparation to

adopt them for magnetization. The soft-iron caps renderthe grinding of the poles unnecessary. The attractivepower of the magnet is scarcely inferior to that of a steelmagnet of the same dimensions, whilst the economy inconstruction is nearly as 4 to 1 ; the cast-iron magnetweighing 72 lbs., lifts 140 lbs.

Powerful horse-shoe steel magnet, of 100 plates, adaptedfor purposes requiring high magnetic power. It weighsabout 39 lbs, and will support nearly 250 lbs. with around-faced keeper.

[The Rev. Dr. Scoresby appears to have been the firstto employ thin sheet steel for the construction of powerfulpermanent magnets. His idea being that, as magnetismappeared to reside principally on the surface of the metal,by multiplying the number of surfaces the power of thecompound bar would be increased. Mr. Hearder, manyyears since, constructed powerful magnets from cast iron,and was certainly the first to use that material for thepurpose; and the power which can be induced is certainlyvery great -with the soft-iron caps.—R. H.]

Medico-galvanic apparatus, with graduated regulator,employed to administer galvanic electricity. Its improvedconstruction consists in the proper adjustment of thelength and thickness of the generating or primary coilto the electro-motive force of the battery, by which thebattery-surface is much reduced, and a higher amount ofmagnetism produced in the iron core.

440 Jodle, James Prescott , F.R.S., Acton Square,Salford — Inventor.

Electro-magnet, constructed of a plate of well-annealedwrought-iron, tapered to the poles. The iron is renderedmagnetic by transmitting the voltaic electricity throughthe bundle of copper wires (fifty yards long, and weighingone hundredweight) with which it is enveloped. Armatureto the same.

Pair of tapered armatures, to concentrate the magneticforce when the electro-magnet is excited by a feeblevoltaic current, and to direct the magnetic action to anyrequired object.